July is TECHNICALLY over but I got these photos and video in July, so I will make this the July post.
I will be talking a bit about a few insects that I have found in my backyard. Summer is the height of insect activity.
The theme for this post is cool insect communication interactions.
Communication? Insects interact? What?
So, I have a really tall sunflower growing in my front yard, it is huge, over 8 feet tall. Scurrying across the underside of its ginormous leaves are these large ants. The ants as you see in the picture are walking amongst smaller insects that cover the underside of the leaf. These ants are tending the treehoppers (the smaller insects which belong to the family Membracidae). The ants are basically farming or ranching the treehoppers for the honeydew that the treehoppers exude. The treehoppers feed off of the juices found in the plant. They then excrete honeydew which is sugary waste water that the insects do not need, but the ants find rather tasty. So the ants tend to these treehoppers, providing protection for the treehoppers against predators while also getting a tasty, energy laden snack for themselves. A similar association or relationship is also found between ants and aphids.
Treehoppers are known for communicating amongst themselves using vibrational signals. They vibrate their abdomen against the leaf or stem of a plant and this signal is transmitted though the plant to a receiver (another treehopper or animal). In this manner they can communicate to their offspring if predators are nearby or signal in search of a mate. They can even communicate to the tending ants if a predator is attacking them. The ants can then chase away the predator. Given that the treehoppers and the ants benefit in this interaction, we call this a mutualism as both partners in the interaction benefit.
Talking about communication and signals, this youtube video I posted (youtu.be/vqJHyrVd9W4) is of a conehead katydid calling for a mate. These are common throughout the Midwest US. This specific one is the Nebraska conehead katydid (Neoconocephalus nebracensis). Their calls can be heard all night along grassy roadside ditches and in field or …in this case...backyards.
Conehead katydids like other katydid species (family Tettigoniidae) make their calls by rubbing their wings together. Crickets (family Grillidae) also call or chirp by rubbing their wings together. Similar to crickets and katydids are grasshoppers. Most commonly seen are the short-horned grashoppers (Family Accrididae), which are generally more robust in appearance then crickets or katydids and have shorter antennae. They call by either rubbing their wings or wings and hindlegs together. You will often see these during the day jumping and flying close to the ground. You might hear them first as their wings make noise when flying and some have brightly colored wings.
Many conehead katydids have a continuous call, one long uninterrupted buzz, but the Nebraska conehead has a discontinuous call, with short phrases interspersed with silence. Males in a chorus of this species will synchronize their calls with their neighbors.
The calls of these katydids are really just another type of vibrational signal, except that we can hear them, so they are called acoustic signals.
If you are interested in learning about more insect calls check out this awesome site: http://songsofinsects.com/
It is the work of two amazing naturalists.